JP2018145433A - Method for lubricating surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for lubricating a surface coated with a diamond-like carbon (DLC) film or coating which is in contact with a surface containing iron.SOLUTION: The present invention comprises a method of lubricating the contact between a first surface coated with a hydrogenous carbon film or coating of type a-C:H, ta-C:H, a-C:H:Me or a-C:H:X, as classified by VDI-standard VDI 2840 and a second surface containing iron, preferably steel surface. The method comprises a step for supplying to the contact a lubricating oil composition comprising a major amount of an oil of lubricating viscosity and (a) an oil-soluble or oil-dispersible molybdenum compound in an amount such as to provide between 150 and 1000 ppm by mass of molybdenum to the lubricating oil composition, and (b) between 0.1 and 5% by mass with respect to the mass of the lubricating oil composition of a polymeric organic friction modifier, the organic friction modifier being the reaction product of (i) a functionalized polyolefin, (ii) a polyether, (iii) a polyol and (iv) a monocarboxylic acid chain terminating group.SELECTED DRAWING: None

Description

  The present invention relates to a method of lubricating a surface coated with a diamond-like carbon (DLC) film or coating in contact with a surface comprising iron, preferably made of steel.

  The following diamond-like carbon (DLC) is a common name commonly used to describe a wide range of amorphous carbon materials. The material is usually given in the form of a film or coating and is characterized by mechanical properties such as hardness, which are similar to, but not exactly the same as, the mechanical properties of diamond. DLC can be hydrogenated or can be non-hydrogenated and is generally produced utilizing PVD or CVD techniques. In addition to carbon (and hydrogen in the case of hydrogenated DLC), DLC can contain other chemical elements as well, such as nitrogen, silicon or fluorine or metal dopants. Metals are more commonly used than other elements, with metals such as tungsten and titanium being the most common. DLC films and coatings can have high hardness (about 3-22 GPa), low roughness, low dry friction coefficient, and transparency across the major portion of the electromagnetic spectrum. In general, DLC films and coatings contain a wide range of amorphous carbon materials, where at least some of the carbon atoms are bonded within a chemical structure similar to that of diamond, but span a long distance of diamond. Lack of crystal order. The Association of German Engineers (VDI) has devised a classification system for DLC films that systematizes various types of films based on their physical and chemical properties. ing. It is published as VDI-standard VDI 2840 and gives a regular classification and nomenclature so that the various types of DLC films can be identified without room for misunderstanding. VDI 2840 identifies seven types of DLC films:

・ Amorphous carbon film without hydrogen, named aC,
・ A tetrahedral hydrogen-free amorphous carbon film named ta-C,
・ Amorphous carbon film named aC: Me containing metal and not containing hydrogen,
A hydrogen-containing amorphous carbon film named aC: H,
A tetrahedral hydrogen-containing amorphous carbon film named ta-C: H,
A hydrogen-containing amorphous carbon film containing a metal, named aC: H: Me,
A modified hydrogen-containing amorphous carbon film named aC: H: X.
The tetrahedral film described above has higher levels of sp ³ carbon bonds compared to other types where the sp ² carbon bonds are more prevalent. Metal dopants (represented by Me) include tungsten, titanium and the like, and X in its modified structure can be nitrogen, silicon, boron and the like. Hydrogenated films typically contain up to 50 atomic percent hydrogen and usually contain at least 5 atomic percent hydrogen.
Many methods for directly depositing DLC films or coatings are known in the art and can be mixed with (i) hydrogen and / or inert gases and / or other gases, including doping elements Direct ion beam deposition, dual ion beam deposition, glow discharge, radio frequency (RF) plasma, direct current (DC) plasma or microwave plasma deposition from carbon-containing gas or vapor, (ii) solid carbon or doped carbon Includes electron beam deposition, ion assisted deposition, magnetron sputtering, ion beam sputtering, or ion assisted sputtering deposition from a target material, or (iii) a combination of (i) and (ii).

The use of such DLC films in coating internal combustion engine components is described, for example, in US Pat. No. 5,771,873.
Using oil-soluble or oil-dispersible molybdenum compounds in lubricating oil compositions to reduce friction against engine parts where steel-on-steel contact occurs and to provide wear protection It is common. Both dinuclear molybdenum compounds (ie compounds containing 2 molybdenum atoms) and trinuclear molybdenum compounds (ie compounds containing 3 molybdenum atoms) provide considerable benefits. For example, from EP 1 426 508 A1, it is known that both dinuclear and trinuclear molybdenum compounds result in friction reduction at the DLC-to-DLC contact. However, in many engines there are parts made of a substance containing iron (generally steel), which are in contact with a part provided with a DLC film or coating. Studies have shown that oil-soluble molybdenum compounds behave differently at DLC-to-steel contacts, so that the DLC coated surface has a higher ratio up to its steel mating surface and the mating surface is another DLC coating. If it is a surface, it is worn out to an extent that it is not observed (for example, I Sugimoto, Transactions of the Japan Society of Mechanical Engineers, Series A, Vol. 78, No. 786, pp. 213-222 checking).

The present invention provides that the contact between a surface with a particular type of DLC film or coating and a surface comprising iron, preferably steel, is identified as an oil-soluble or oil-dispersible molybdenum compound. Is based on the discovery that it can be effectively lubricated by using a lubricating oil composition comprising a combination with an organic friction modifier of the type Thus, the present invention utilizes the friction reducing properties provided by the molybdenum compound without compromising the wear protection provided by the lubricating oil composition. It is noteworthy that the wear behavior investigated by the present invention is evident for some, but not all, of the DLC coating types according to the VDI 2840 classification scheme.
Thus, in a first aspect, the present invention is based on the classification according to VDI-standard VDI 2840, aC: H, ta-C: H, aC: H: Me or aC: H: X type hydrogenous Provided is a method of lubricating a contact between a first surface coated with a carbon film or coating and a second surface comprising ferrous, preferably steel, the method Comprises supplying a lubricating oil composition to the contact portion, the lubricating oil composition comprising a large amount of lubricating viscosity oil and (a) the lubricating oil composition on a mass basis. An oil-soluble or oil-dispersible molybdenum compound in an amount to give between 150 and 1,000 ppm of molybdenum, and (b) a polymer system between 0.1 and 5% by weight with respect to the weight of the lubricating oil composition An organic friction modifier comprising: (i) a functionalized polyolefin; (ii) a polyether; iii) reaction products of polyols and (iv) monocarboxylic acid chain terminating groups.

In a second aspect, the present invention relates to a hydrogen-containing carbon film or coating of the aC: H, ta-C: H, aC: H: Me or aC: H: X type based on the classification according to VDI-standard VDI 2840 An internal combustion engine having one or more components coated with, wherein during operation of the engine, the components are in contact with a surface comprising iron, preferably steel, The reservoir contains a lubricating oil composition, the lubricating oil composition comprising: (a) an oil having a large amount of lubricating viscosity; and (a) 150 to 1,000 ppm of the lubricating oil composition on a mass basis. An oil-soluble or oil-dispersible molybdenum compound in an amount to provide molybdenum in between, and (b) between 0.1 and 5% by weight of a polymeric organic friction modifier with respect to the weight of the lubricating oil composition The organic friction modifier comprises (i) a functionalized polyolefin, (ii) a polyether, (iii) a polyol A le and (iv) the reaction product of a monocarboxylic acid chain terminators group.
The reservoir in the engine can be a crankcase sump in a 4-stroke engine, from which it is distributed around the engine for lubrication. The present invention is applicable to 2-stroke and 4-stroke spark ignition and compression ignition engines.

In a third aspect, the present invention relates to a hydrogen-containing carbon film or coating of the aC: H, ta-C: H, aC: H: Me or aC: H: X type based on classification according to VDI-standard VDI 2840. Providing a use of a lubricating oil composition for lubricating an internal combustion engine having one or more components coated with the components, the components comprising iron during operation of the engine The lubricating oil composition, preferably in contact with a steel surface, comprising: an oil having a high amount of lubricating viscosity; and (a) between 150 and 1,000 ppm molybdenum by weight on the lubricating oil composition An oil-soluble or oil-dispersible molybdenum compound in an amount to give, and (b) between 0.1 and 5% by weight of a polymeric organic friction modifier, relative to the weight of the lubricating oil composition, Organic friction modifiers include (i) functionalized polyolefin, (ii) polyether, (iii) polyol and Beauty (iv) the reaction product of a monocarboxylic acid chain terminators group.
In a fourth aspect, the present invention provides a hydrogen-containing carbon film or coating of the aC: H, ta-C: H, aC: H: Me or aC: H: X type based on the classification according to VDI-standard VDI 2840 Between one or more components of an internal combustion engine, coated with, and one or more components of the combustion engine having a surface comprising iron, preferably steel Provided is the use of a lubricating oil composition to reduce friction and prevent its wear, the lubricating oil composition comprising an oil having a high lubricating viscosity, and (a) the lubricating oil composition An oil-soluble or oil-dispersible molybdenum compound in an amount to give between 150 and 1,000 ppm molybdenum on a weight basis, and (b) 0.1 to 5% by weight with respect to the weight of the lubricating oil composition Between the polymer-based organic friction modifier, the organic friction modifier comprising (i) a functionalized polyolefin A (ii) a polyether, (iii) a polyol and (iv) the reaction product of a monocarboxylic acid chain terminators group.

Preferably, the oil-soluble or oil-dispersible molybdenum compound (a) is present in the lubricating oil composition at a weight basis of 300 to 1,000 ppm, preferably between 400 and 1,000 ppm, such as 500 to 1,000 ppm. Is present in such an amount as to provide molybdenum in between. The molybdenum content of the lubricating oil composition is as measured by ASTM D5185.
As described in more detail below, the oil-soluble or oil-dispersible molybdenum compound (a) can be a mixture of two or more molybdenum compounds, and in a preferred embodiment, the oil-soluble or oil-dispersible molybdenum compound (a) The soluble or oil-dispersible molybdenum compound (a) is a mixture of two or more molybdenum compounds. In these examples, the amount of molybdenum in the lubricating oil composition referred to herein is the combined total amount of molybdenum provided by the mixture of compounds.
Preferably, the oil-soluble or oil-dispersible molybdenum compound (a) is one or more molybdenum dithiocarbamate, molybdenum dithiophosphate, molybdenum dithiophosphinate, molybdenum xanthate, molybdenum thioxanthate or sulfurized. Contains molybdenum. In a preferred embodiment, the oil-soluble or oil-dispersible molybdenum compound comprises one or more molybdenum dithiocarbamates. Most preferred are dinuclear and trinuclear molybdenum dithiocarbamates. In one embodiment, the oil-soluble or oil-dispersible molybdenum compound comprises one or more dinuclear molybdenum dithiocarbamates. In another embodiment, the oil-soluble or oil-dispersible molybdenum compound comprises one or more trinuclear molybdenum dithiocarbamates. In yet another embodiment, the oil-soluble or oil-dispersible molybdenum compound comprises a mixture of one or more dinuclear molybdenum dithiocarbamates and one or more trinuclear molybdenum dithiocarbamates. Including. These molybdenum compounds are described in more detail below.

In particular, the present invention provides a spark ignition or compression ignition type 2-stroke or 4 having a part or member with a DLC film or coating in contact with a part or member having an iron, preferably steel surface. -Applied for lubrication of stroke internal combustion engine. Examples of such parts and members include camshafts, especially cam lobes; pistons, especially piston skirts; cylinder liners; and valves.
Various features of the invention that are applicable to all aspects are described in more detail below.
(a) Oil-soluble or oil-dispersible molybdenum compounds. Examples of oil-soluble or oil-dispersible molybdenum compounds (a) include molybdenum dithiocarbamate, dithiophosphate, dithiophosphinate, xanthate, thioxanthate and Mention may be made of sulfides and mixtures thereof.
In addition, the molybdenum compound may be an acidic molybdenum compound. These compounds react with basic nitrogen compounds as measured by the titration procedure of ASTM test D-664 or D-2896 and are typically hexavalent. Molybdate, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkali metal molybdates and other molybdenum salts such as sodium hydrogen molybdate, MoOCl ₄ , MoO ₂ Br ₂ , Mo ₂ O ₃ Cl ₆ , Molybdenum trioxide or similar acidic molybdenum compounds are included.
Included among the molybdenum compounds useful in this invention are organomolybdenum compounds having the formulas: Mo (ROCS ₂ ) ₄ and Mo (RSCS ₂ ) ₄ , where R is typically 1-30. And preferably an organic group selected from the group consisting of alkyl having 2 to 12 carbon atoms, aryl, aralkyl and alkoxyalkyl, and most preferably alkyl having 2 to 12 carbon atoms . Particularly preferred is a dialkyldithiocarbamate of molybdenum.
A further group of oil-soluble or oil-dispersible molybdenum compounds are dinuclear molybdenum compounds. An example is represented by the following formula:

Here, R _{1 to} R ₄ independently represent a linear, branched or aromatic hydrocarbyl group having 1 to 24 carbon atoms, and X _{1 to} X ₄ independently represent an oxygen atom or a sulfur atom. Means. These four hydrocarbyl groups, R _{1 to} R _4, may be the same or different from each other.
Another group of oil-soluble or oil-dispersible molybdenum compounds useful in this invention are trinuclear molybdenum compounds, especially those having the formula Mo ₃ S _k L _n Q _z , and mixtures thereof; Where L is an independently selected ligand comprising an organic group having a sufficient number of carbon atoms to render the compound soluble or dispersible in the oil, and n is 1-4. , K varies from 4 to 7, Q is selected from the group consisting of neutral electron donor compounds such as water, amines, alcohols, phosphines, and ethers, and z is in the range of 0 to 5 and non -Includes stoichiometric values. In examples where n is 3, 2 or 1, an appropriately charged ionic species is required to impart electrical neutrality to the trinuclear molybdenum compound. The ionic species can be of any valence, such as monovalent or divalent. Further, the ionic species may be a negatively charged, i.e. anionic species, or may be a positively charged, i.e. cationic species, or a combination of anions and cations. Such terms are known to those skilled in the art. The ionic species can be covalently linked, i.e. coordinated within the core to one or more molybdenum atoms, or via electrostatic bonds or interactions as in the case of counterions, or covalently. It can be present in the compound through an intermediate bond form between bonding and electrostatic bonding. Examples of anionic species include disulfides, hydroxides, alkoxides, amides and thiocyanates or derivatives thereof, preferably the anionic species is a disulfide ion. Examples of cationic species include ammonium ions and metal ions such as alkali metal ions, alkaline earth metal ions or transition metal ions, preferably ammonium ions such as [NR ₄ ] ⁺ , where R is independently H Or it is an alkyl group, and it is more preferable that R is H, that is, [NH ₄ ] ⁺ . At least 21 total carbon atoms, such as at least 25, at least 30, or at least 35 carbon atoms should be present in the organic group of all the ligands.
The ligand is independently selected from the group consisting of those listed below, and mixtures thereof:

Wherein X, X ₁ , X ₂ and Y are independently selected from the group consisting of oxygen and sulfur, and wherein R ₁ , R ₂ and R are independently selected from hydrogen and organic groups, the groups being the same But it can be different. Preferably, the organic group is a hydrocarbyl group, such as an alkyl (eg, in which the carbon atom attached to the remainder of the ligand is primary or secondary), aryl, substituted aryl and ether groups. More preferably, each ligand has the same hydrocarbyl group.
The term “hydrocarbyl” refers to a substituent having a carbon atom bonded directly to the remainder of the ligand, and in the context of this invention is exclusively hydrocarbyl in character. Such substituents include those listed below: hydrocarbon substituents, ie aliphatic (eg, alkyl or alkenyl), alicyclic (eg, cycloalkyl or cycloalkenyl) substituents, aromatic-, Aliphatic- and alicyclic-substituted aromatic nuclei and the like, as well as cyclic substituents whose rings are completed through another part of the ligand (ie any two indicated substituents Together can form an alicyclic group), a substituted hydrocarbon substituent, i.e., a non-hydrocarbon group that does not alter the predominant hydrocarbyl properties of the substituent in the context of the present invention. Including. The person skilled in the art is confident that suitable groups (e.g. halo, in particular chloro and fluoro, amino, alkoxyl, mercapto, alkyl mercapto, nitro, nitroso and sulphoxy) and heterosubstituents, i.e. exclusively exclusively hydrocarbons in the context of the present invention. However, it will recognize substituents composed of carbon atoms, except for those atoms that contain non-carbon atoms present in the chain or ring.

Importantly, the organic group of the ligand has a sufficient number of carbon atoms to render the compound soluble or dispersible in the oil. For example, the number of carbon atoms in each group generally ranges between 1 and 100, preferably between 1 and 30, and more preferably between 4 and 20. Preferred ligands include dialkyl dithiophosphates, alkyl xanthates, and dialkyl dithiocarbamates, of which the more preferred are dialkyl dithiocarbamates. An organic ligand containing two or more of the above functionalities can similarly function as a ligand and can bind to one or more of its cores. Those skilled in the art will recognize that the formation of compounds useful in the present invention requires the selection of ligands with the appropriate charge in order to balance the charge on the core.
A compound having the formula: Mo ₃ S _k L _n Q _z has a cationic core surrounded by an anionic ligand and is represented by the following structure, for example, and a net of +4 Have a charge:

Consequently, in order to solubilize these cores, the total charge contained in all of the ligands must be -4. Four monoanionic ligands are preferred. Without wishing to be bound by any theory, two or more trinuclear cores can be bound or interconnected by one or more ligands, and the ligands are multidentate It is thought that it can be. Such a structure falls within the scope of the present invention. This includes the case of multidentate ligands with multiple linkages to a single core. It is believed that oxygen and / or selenium can be exchanged for sulfur in the core (s).
Oil-soluble or oil-dispersible trinuclear molybdenum compounds can be prepared in a suitable liquid (s) and / or solvent (s) in a molybdenum source, for example (NH ₄ ) ₂ Mo ₃ S ₁₃ Prepared by reacting (H ₂ O) (where n varies between 0 and 2, including non-stoichiometric values) and a suitable ligand source, such as a tetraalkylthiuram disulfide. Can do. Other oil-soluble or oil-dispersible trinuclear molybdenum compounds can be obtained from a molybdenum source, such as (NH ₄ ) ₂ Mo ₃ S ₁₃ · n (H ₂ O), in a suitable solvent (s). It can be formed during the reaction of a ligand source, such as tetraalkylthiuram disulfide, dialkyldithiocarbamate, or dialkyldithiophosphate, and a sulfur-abstracting agent, such as cyanide ion, nitrite ion, or substituted phosphine. Alternatively, a trinuclear molybdenum-sulfur halide salt such as [M ′] ₂ [Mo ₃ S ₇ A ₆ ] (where M ′ is a counter ion and A is a halogen such as Cl, Br, or I) ) In a suitable liquid (s) and / or solvent (s) with a ligand source, such as a dialkyldithiocarbamate or dialkyldithiophosphate, to produce an oil-soluble or oil-dispersible trinuclear A molybdenum compound can be formed. The suitable liquid and / or solvent can be, for example, aqueous or organic.

The oil solubility or dispersibility of a compound can be affected by the number of carbon atoms in the organic group of its bound ligand. In the compounds used in the present invention, at least 21 total carbon atoms should be present in the organic groups of all the ligands. Preferably, the selected ligand source has a sufficient number of carbon atoms in its organic group to render the compound soluble or dispersible in the lubricating composition.
The oil-soluble or oil-dispersible molybdenum compound is preferably an organic molybdenum compound. Further, the molybdenum compound is preferably selected from the group consisting of molybdenum dithiocarbamate (MoDTC), molybdenum dithiophosphate, molybdenum dithiophosphinate, molybdenum xanthate, molybdenum thioxanthate, molybdenum sulfide, and mixtures thereof.
Most preferably, the oil-soluble or oil-dispersible molybdenum compound comprises one or more molybdenum dithiocarbamates. In preferred embodiments, the oil-soluble or oil-dispersible molybdenum compound comprises one or more dinuclear molybdenum dithiocarbamates, or comprises one or more trinuclear molybdenum dithiocarbamates.
In a most preferred embodiment, the oil-soluble or oil-dispersible molybdenum compound comprises a mixture of one or more dinuclear molybdenum dithiocarbamates and one or more trinuclear molybdenum dithiocarbamates. Including. In this embodiment, the ratio of dinuclear molybdenum dithiocarbamate to trinuclear molybdenum dithiocarbamate is from 1: 9 to 9: 1 in terms of the mass of molybdenum provided to the lubricating oil composition by each type of molybdenum compound. Preferably it is 1: 4 to 4: 1, more preferably 1: 2 to 2: 1, for example 1: 1. As discussed above, in this embodiment, the amount of molybdenum in the lubricating oil composition referred to herein is the combined total amount of molybdenum provided by the mixture of compounds.

(b) Polymeric organic friction modifier As with all polymers, the polymeric organic friction tonicity agent (b) useful in the present invention comprises a mixture of molecules of various sizes. Suitably, the majority of the molecules have a molecular weight in the range of 1,000 to 30,000 daltons.
Preferably, the functionalized polyolefin (i) is derived from a polymer of monoolefins having 2 to 6 carbon atoms, such as ethylene, propylene, butene and isobutene. The functionalized polyolefin of the present invention suitably comprises a chain having 15 to 500, preferably 50 to 200 carbon atoms. Preferably, the monoolefin polymer is a polyisobutylene polymer or a derivative thereof.
The functionalized polyolefin (i) can contain diacid or anhydride functional groups derived from the reaction of the polyolefin with an unsaturated diacid or anhydride. The functionalized polyolefin is suitably functionalized by reaction with maleic anhydride.
In a preferred embodiment, the functionalized polyolefin (i) is a polyisobutylene polymer that has been reacted with maleic anhydride to form polyisobutylene succinic anhydride (PIBSA). Suitably, the PIBSA has a molecular weight in the range of 300 to 5,000 Da, preferably 500 to 1,500 Da and especially 800 to 1,200 Da. PIBSA is a commercially available compound produced by an addition reaction between polyisobutylene having a terminal unsaturated group and maleic anhydride.
Alternatively, the functionalized polyolefin (i) can be functionalized by an epoxidation reaction with a peracid, such as perbenzoic acid or peracetic acid.

The polyether (ii) can contain, for example, polyglycerol or polyalkylene glycol. In a preferred embodiment, the polyether is a water soluble alkylene glycol, such as polyethylene glycol (PEG). Suitably the PEG has a molecular weight in the range of 300 to 5,000 Da, more preferably 400 to 1,000 Da and especially 400 to 800 Da. In a preferred embodiment, the polyether is PEG ₄₀₀ , PEG ₆₀₀ or PEG ₁₀₀₀ . Alternatively, mixed poly (ethylene-propylene) glycol or mixed poly (ethylene-butylene) glycol can be used. Alternatively, the polyether is derived from a diamine or diol containing acidic groups such as carboxylic acid groups, sulfonyl groups (e.g. sulfonyl styrene groups), amino groups (e.g. tetraethylenepentamine or polyethyleneimine) or hydroxyl groups. obtain.
The polyether (ii) suitably has a molecular weight of 300 to 5,000 Da, more preferably 400 to 1,000 Da or 400 to 800 Da.
The functionalized polyolefin (i) and the polyether (ii) can form block copolymer units.
The functionalized polyolefin (i) and the polyether (ii) can be directly bonded to each other and / or they may be bonded together by a backbone moiety.

The polyol reactant (iii) according to the polymeric friction modifier useful in the present invention suitably combines the functionalized polyolefin (i) and polyether (ii) reactants together. Gives the main chain part that can be. The polyol can include diols, triols, tetraols, or related dimers or trimers or higher oligomers of such compounds. Suitable polyols include glycerol, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, pentaerythritol, dipentaerythritol, tripentaerythritol and sorbitol. In a preferred embodiment, the polyol (iii) is glycerol.
The polymeric friction modifier useful in the present invention comprises a monocarboxylic acid chain termination group (iv). Any carboxylic acid is suitable as a chain terminating group. Suitable examples include C _2-36 carboxylic acids, preferably C _6-30 carboxylic acids, and more preferably C _12-22 carboxylic acids. The carboxylic acid may be linear or branched, saturated or unsaturated. In a preferred embodiment, the carboxylic acid chain terminating group (iv) comprises one or more lauric acid, erucic acid, isostearic acid, palmitic acid, oleic acid and linoleic acid. In a preferred embodiment, the carboxylic acid chain terminating group is an aliphatic carboxylic acid, and a particularly preferred fatty acid is oleic acid. A suitable and preferred oleic acid source is tall oil fatty acid.
The polymeric organic friction modifier (b) suitably has an average molecular weight of 1,000 to 30,000 Da, preferably 1,500 to 25,000, more preferably 2,000 to 20,000 Da.

The polymeric organic friction modifier (b) suitably has an acid number of less than 20, preferably less than 15 and more preferably less than 10. The polymeric organic friction modifier (b) suitably has an acid number greater than 1, preferably greater than 3 and more preferably greater than 5. In a preferred embodiment, the friction modifier (B1) has an acid value in the range of 6-9.
Suitably, the polymeric organic friction modifier (b) is as described in International Patent Application WO 2011/107739.
In a preferred embodiment according to all aspects of the present invention, the polymeric organic friction modifier (b) comprises (i) maleated polyisobutylene (PIBSA), (ii) polyethylene glycol (PEG), (iii) glycerol and ( iv) A reaction product of tall oil fatty acid. Preferably, the maleated polyisobutylene polyisobutylene has an average molecular weight around 950 amu and an approximate saponification number of 98 mg KOH / g. Preferably, the PEG has a hydroxyl number of 190 mg KOH / g. A suitable product is 110 g maleated polyisobutylene, 72 g PEG, 5 g glycerol and 25 g tall oil fatty acid, a glass round bottom flask equipped with a mechanical stirrer, isomantle heater and overhead condenser. Can be manufactured by charging. This reaction occurs in the presence of 0.1 g of the esterification catalyst tetrabutyl titanate at 200-220 ° C. with removal of water to a final acid number of 10 mg KOH / g.
Preferably, the polymeric organic friction tonicity agent (b) of the present invention is comprised between 0.1 and 3%, more preferably between 0.1 and 1.5% by weight in the lubricating oil composition, with respect to the weight of the lubricating oil composition. Exists in the amount between.

Oil with lubricating viscosity The oil with the above lubricating viscosity (often referred to as `` base stock '' or `` base oil '') is the main liquid component of the lubricating oil, including in the final lubricating oil (for example, Alternatively, additives and possibly other oils are blended to produce a lubricating composition). Base oils are useful for making concentrates and for making lubricating oil compositions therefrom, and can be selected from natural (plant, animal or mineral) and synthetic lubricating oils and mixtures thereof.
The above base stocks are published by the American Petroleum Institute (API): “Engine Oil Licensing and Certification System”, Industry Services Department, 14th. Edition, December 1996, Addendum 1, December 1998. Typically, the base stock has a viscosity of preferably 3-12, more preferably 4-10, most preferably 4.5-8 mm ² / s (cSt) at 100 ° C.
The definitions of base stock and base oil in the present invention are defined in the American Petroleum Institute (API) publication: “Engineering Oil Licensing and Certification System”, Industrial Services, 14th Edition, December 1996, Addendum 1, 1998 Identical to that found in December. The publication classifies the base stock as follows:
a) Group I base stock contains less than 90% saturates and / or more than 0.03% sulfur and is 80 when using the test methods specified in Table E-1 below. Has a viscosity index equal to or greater than and less than 120.
b) Group II base stock contains saturates equal to or greater than 90% and sulfur equal to or less than 0.03%, and the test methods specified in Table E-1 below. Has a viscosity index equal to or greater than 80 and less than 120.
c) Group III base stock contains saturates equal to or greater than 90% and sulfur equal to or less than 0.03% and the test methods specified in Table E-1 below. Is used, it has a viscosity index equal to or greater than 120.
d) Group IV base stock is poly α-olefin (PAO).
e) Group V base stock includes all other base stocks not included in Group I, II, III, or IV.

Other oils of lubricating viscosity that can be included in the lubricating oil composition are described in detail below:
Natural oils are hydrorefined, solvent-treated, consisting of animal and vegetable oils (e.g. castor oil and lard oil), liquid petroleum oils and paraffinic, naphthenic and mixed paraffin-naphthene types. Includes mineral oils. Oils with a lubricating viscosity derived from coal or shale are also useful base oils.
Synthetic lubricating oils are hydrocarbon oils such as polymerized and copolymerized olefins (e.g. polybutylene, polypropylene, propylene-isobutylene copolymer, chlorinated polybutylene, poly (1-hexene), poly (1-octene), poly (1- 1-decene)); alkylbenzenes (eg, dodecylbenzene, tetradecylbenzene, dinonylbenzene, di- (2-ethylhexyl) benzene); polyphenols (eg, biphenyl, terphenyl, alkylated polyphenols); and alkylated diphenyl ethers and Including alkylated diphenyl sulfide and derivatives, analogs and homologues thereof.
Another suitable group of synthetic lubricating oils are dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acid and alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid. Esters of acid dimers, malonic acid, alkylmalonic acid, alkenylmalonic acid) with various alcohols (for example, butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol) including. Specific examples of these esters include dibutyl adipate, di- (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, didecyl phthalate Eicosyl sebacate, 2-ethylhexyl diester of linoleic acid dimer, and complex ester formed by reaction of 1 mol sebacic acid with 2 mol tetraethylene glycol and 2 mol 2-ethylhexanoic acid.

Similarly, Esters useful as synthetic oils, C ₅ -C ₁₂ monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylol propane, pentaerythritol, esters prepared from dipentaerythritol and tripentaerythritol Is also included.
Unrefined, refined and re-refined oils can be used in the above compositions of the present invention. Unrefined oils are those obtained directly from natural or synthetic sources without further purification. For example, shale oil obtained directly from retorting operations, petroleum oil obtained directly by distillation or ester oil obtained directly from an esterification process, which is used without further treatment, corresponds to unrefined oil . Refined oils are similar to the unrefined oils except that they are further processed in one or more purification steps with the aim of improving one or more properties. Many such purification techniques, such as distillation, solvent extraction, acid or base extraction, filtration and percolation are known to those skilled in the art. The re-refined oil is obtained by a process similar to that used to obtain the refined oil, which is applied to the refined oil already used in the operation. Such rerefined oils are also known as reclaimed or reprocessed oils and are often incidentally processed by techniques for obtaining approval for spent additives and oil breakdown products.
Other examples of base oil are gas - Two - a Liquid (gas-to-liquid) ( "GTL") base oils, i.e. the base oil, from synthesis gas containing H ₂ and CO, the Fischer - Tropsch (Fisher- It may be an oil derived from a Fischer-Tropsch synthesized hydrocarbon produced using a (Tropsch) catalyst. These hydrocarbons typically require further processing in order to be useful as a base oil. For example, these can be hydroisomerization; hydrocracking and hydroisomerization; dewaxing; or hydroisomerization and dewaxing by methods known in the art.

The composition of the base oil will depend on the specific application of the lubricating oil composition, and the oil formulator will select the base oil to achieve the desired performance characteristics at a reasonable cost. However, the base oil of the lubricating oil composition according to the present invention typically comprises no more than 85% by weight Group IV base oil, the base oil being no more than 70% by weight Group IV base oil, or even no more than 50% by weight. Includes Group IV base oil. The base oil of the lubricating oil composition according to the present invention may comprise 0% by weight Group IV base oil. Alternatively, the base oil of the lubricating oil composition according to the present invention may comprise at least 5%, at least 10% or at least 20% by weight of Group IV base oil. The base oil of the lubricating oil composition according to the present invention may comprise 0-85 wt.%, Or 5-85 wt.%, Alternatively 10-85 wt.% Group IV base oil.
Preferably, the oil or oil blend having the above lubricating viscosity has a viscosity measured by the NOACK test (ASTM D5800) of less than or equal to 20%, preferably less than or equal to 16%, Preferably it is less than or equal to 12%, more preferably less than or equal to 10%. Preferably, the viscosity index (VI) of the oil having the lubricating viscosity is at least 95, preferably at least 110, more preferably up to 120, even more preferably at least 120, even more preferably at least 125, Most preferably, it is about 130-140.
The oil with the above lubricating viscosity constitutes a small amount of additive components (a) and (b) as defined herein and optionally one or more auxiliary additives such as lubricating oil compositions. In combination with supplemental additives as described below. This preparation can be accomplished by adding the additives directly to the oil or by adding them in the form of a concentrate to disperse or dissolve the additives. Additives can be added to the oil by any method known to those skilled in the art, prior to the addition of other additives, either simultaneously with the addition or after the addition.

Preferably, the oil having the lubricating viscosity is present in an amount exceeding 55% by weight, more preferably exceeding 60% by weight and even more preferably exceeding 65% by weight, based on the total weight of the lubricating oil composition. To do. Preferably, the oil having the lubricating viscosity is present in an amount of less than 98% by weight, more preferably less than 95% by weight, and even more preferably less than 90% by weight, based on the total weight of the lubricating oil composition.
When a concentrate is used to produce the lubricating oil composition, the concentrate has a lubricating viscosity of, for example, 3 to 100 parts by weight, for example 5 to 40 parts by weight per part by weight of the concentrate. Can be diluted with oil.
Preferably, the lubricating oil composition is a viscometric descriptor SAE 20WX, SAE 15WX, SAE 10WX, SAE 5WX or SAE 0WX (where X represents any one of 20, 30, 40 and 50) ), And the different viscometric grade characteristics can be found in the SAE J300 classification. In embodiments according to each aspect of the present invention, independently of the other embodiments, the lubricating oil composition is in the form of SAE 10WX, SAE 5WX or SAE 0WX, preferably in the form of SAE 5WX or SAE 0WX, wherein X represents any one of 20, 30, 40 and 50. Preferably X is 20 or 30.
Similarly, the lubricating oil compositions useful in the present invention can include any of the conventional additives listed below (including any additional friction modifiers), which are typically It is used in small amounts, for example to give its standard attendant functions. Similarly, typical amounts for individual components are specified below. All the values listed are given as mass percent active ingredient in the total lubricating oil composition.

The individual additives can be incorporated into the base stock in any convenient manner. Thus, each of the components can be added directly to the base stock by dispersing or dissolving it in the base stock at the desired concentration level. Such blending can occur at ambient or elevated temperatures.
Preferably, all of the additives other than the viscosity modifier and the pour point depressant are blended into a concentrate (or additive package), which is then blended into the base stock to complete. A finished lubricating oil composition is prepared. The use of such concentrates is routine. The concentrate typically includes the additive (s) in appropriate amounts, and the final lubricating oil composition when the concentrate is combined with a predetermined amount of base oil. To give the desired concentration.
The concentrate is conveniently prepared according to the method described in US Pat. No. 4,938,880. This patent describes the preparation of a premix consisting of an ashless dispersant and a metal detergent, which is pre-blended at a temperature of at least about 200 ° C. Thereafter, the premix is cooled to at least 85 ° C. and the additional ingredients are added.
The final crankcase lubricating oil composition can use 2-20% by weight and preferably 4-15% by weight of the concentrate (or additive package), the balance being base oil.
Ashless dispersants keep the oil-insoluble matter resulting from oxidation of the oil in suspension during wear or combustion. These are particularly advantageous in preventing sludge precipitation and varnish formation, especially in gasoline engines.

Ashless dispersants include an oil-soluble polymer-based hydrocarbon backbone having one or more functional groups, which can bind to the particles to be dispersed. Typically, the polymer backbone is functionalized with amine, alcohol, amide, or ester polar moieties, often through bridging groups. For example, the ashless dispersant may include oxazolines, oil-soluble salts, esters, amino-esters, amides and imides of long chain hydrocarbon substituted mono and dicarboxylic acids or anhydrides; thiocarboxylate derivatives of long chain hydrocarbons; Long chain aliphatic hydrocarbons containing polyamines directly attached thereto; and selecting from Mannich condensation products formed by condensing long chain substituted phenols with formaldehyde and polyalkylene polyamines Can do.
The oil of these dispersants - soluble polymeric hydrocarbon backbone is typically an olefin polymer or polyene, especially primary molar amount of (i.e., greater than 50 mole%), C ₂ ~C ₁₈ olefins (e.g., ethylene , Propylene, butylene, isobutylene, pentene, octene-1, styrene) and typically polymers containing C _{2 to} C ₅ olefins. The oil-soluble polymeric hydrocarbon backbone can be a homopolymer (eg, polypropylene or polyisobutylene) or a copolymer of two or more such olefins (eg, ethylene and an α-olefin such as propylene or butylene). Or a copolymer of two different α-olefins. Other copolymers are those in which a small molar amount, for example 1 to 10 mol%, of the copolymer monomer is an α, ω-diene, for example a C _{3 to} C ₂₂ non-conjugated diolefin (for example between isobutylene and butadiene). Copolymers, or copolymers of ethylene, propylene and 1,4-hexadiene or 5-ethylidene-2-norbornene). Preference is given to polyisobutenyl (Mn: 400 to 2,500, preferably 950 to 2,200) succinimide dispersants.

The viscosity modifier (VM) functions to impart high temperature and low temperature operability to the lubricating oil composition. The VM used may have only its function or may be multifunctional.
Multifunctional viscosity modifiers that also function as dispersants are likewise known. Suitable viscosity modifiers include polyisobutylene, copolymers of ethylene and propylene and higher α-olefins, polymethacrylates, polyalkylmethacrylates, methacrylate copolymers, copolymers of unsaturated dicarboxylic acids and vinyl compounds, styrene and acrylate esters And partially hydrogenated copolymers of styrene / isoprene, styrene / butadiene, and isoprene / butadiene, and partially hydrogenated homopolymers of butadiene and isoprene and isoprene / divinylbenzene.
Metal-containing or ash-forming detergents may be present, and these act as both detergents to reduce or remove deposits and as acid neutralizers or corrosion inhibitors, thereby causing wear. Reduce corrosion and extend engine life. Detergents generally include a polar head with a long hydrophobic tail, which includes a metal salt of an acidic organic compound. These salts can contain a substantially stoichiometric amount of the metal, where these salts are usually described as normal or neutral salts and are typically 0-80 ASTM D It has a total base number (TBN) that can be measured by -2896. A large amount of metal base can be included by reacting an excess amount of a metal compound, such as an oxide or hydroxide, with an acidic gas such as carbon dioxide. The resulting overbased detergent comprises a neutralized detergent as the outer layer of a metal base (eg, carbonate) micelle. Such overbased detergents can have a TBN of 150 or more, and typically 250 to 450 or more. Detergents that can be used are metals, especially alkaline systems such as sodium, potassium, lithium and magnesium, oil-soluble neutral and overbased sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, and naphthenates and others Of oil-soluble carboxylates. Preferred are neutral or overbased calcium and magnesium phenates and sulfonates, especially calcium.

Other friction modifiers include oil-soluble amines, amides, imidazolines, amine oxides, amidoamines, nitriles, alkanolamides, alkoxylated amines and ether amines; polyol esters; and esters of polycarboxylic acids.
Metal salts of dihydrocarbyl dithiophosphate are often used as antiwear and antioxidant agents. The metal can be an alkali metal or alkaline earth metal, or aluminum, lead, tin, molybdenum, manganese, nickel or copper. These typically first form dihydrocarbyl dithiophosphoric acid (DDPA) by reaction of one or more alcohols or phenols with P ₂ S ₅ , and then the formed DDPA with a zinc compound. It can be produced according to known techniques by summing. For example, dithiophosphoric acid can be prepared by reacting a mixture of primary or secondary alcohols. Alternatively, a large number of dithiophosphoric acids can be prepared, in which the hydrocarbyl group on one is exclusively secondary in nature and the hydrocarbyl group on the other is exclusively primary in nature. To make the zinc salt, any basic or neutral zinc compound can be used, but oxides, hydroxides and carbonates are most commonly used. Commercial additives often contain an excess of zinc due to the use of an excess of the basic zinc compound in the neutralization reaction.

ZDDP provides excellent wear protection at a relatively low cost and also functions as an antioxidant. However, there is some evidence that phosphorus in lubricants can shorten the effective life of automotive emission catalysts. Accordingly, the lubricating oil composition of the present invention preferably contains 0.8 mass% or less, for example 50 ppm to 0.06 mass% phosphorus. Regardless of the amount of phosphorus, preferably the lubricating oil composition contains 0.5 wt% or less, preferably 50 ppm to 0.3 wt% sulfur, and the amount of sulfur and phosphorus is measured according to ASTM D5185.
Antioxidants or antioxidants reduce the tendency of the base stock to degrade during operation, which is due to products from oxidation, such as sludge and varnish-like deposits on metal surfaces, and due to increased viscosity. It can be proved. Such oxidation inhibitors include hindered phenols, preferably alkaline earth metal salts of alkylphenol thioesters with C _{5 to} C ₁₂ alkyl side chains, calcium nonylphenol sulfides, ashless oil-soluble phenates and sulfurized phenates, phosphorus -Phosphosulfurized or sulfurized hydrocarbons, phosphites, metal thiocarbamates, oil-soluble copper compounds described in US Patent No. 4,867,890, and molybdenum-containing compounds.
A corrosion inhibitor selected from the group consisting of nonionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, and anionic alkyl sulfonic acids can be used.

Copper- and lead-supported corrosion inhibitors can be used, but are typically not required in the lubricating oil compositions of the present invention. Typically such compounds are thiadiazole polysulfides containing 5 to 50 carbon atoms, derivatives thereof and polymers thereof. Derivatives of 1,3,4-thiadiazole are typical, such as those described in US Pat. Nos. 2,719,125; 2,719,126; and 3,087,932. Other similar materials are described in U.S. Pat. Nos. 3,821,236; 3,904,537; 4,097,387; 4,107,059; 4,136,043; 4,188,299; and 4,193,882. Other additives are thiadiazole thio and polythiosulfenamides, such as those described in GB-A-1,560,830. Benzotriazole derivatives are also included in this group of additives. When these compounds are included in the lubricating oil composition, they are preferably present in an amount not exceeding 0.2 mass% active ingredient.
A small amount of a demulsifying component can be used. A preferred demulsifying component is described in EP-A-330 522. This is obtained by reaction of alkylene oxide with an adduct obtained by reacting bis-epoxide with a polyhydric alcohol. The demulsifier should be used at a level not exceeding 0.1 mass% active ingredient. A treatment rate of 0.001 to 0.05 mass% active ingredient is preferred.
Pour point depressants, also known as lube oil improvers, lower the minimum temperature at which the fluid can flow or be injected. Such additives are well known. Typical of these additives that improve the low temperature fluidity of the fluid are C ₈ -C ₁₈ dialkyl fumarate / vinyl acetate copolymers and polyalkyl methacrylates.
Foam control can be provided by a number of compounds including polysiloxane type antifoams such as silicone oil or polydimethylsiloxane.

As used herein, the term `` comprising '' (or its synonymous terms, e.g. `` comprises '') means the presence of a stated feature, integer, step or ingredient, but one or It does not exclude the presence or addition of more than one other feature, integer, step, ingredient or population thereof, as the term “comprising” (or its synonymous terms) is used herein “Consisting essentially of” (and its synonymous terms) falls within its scope and is a preferred embodiment, resulting in the term “consisting of” (and its equivalents). Is a preferred embodiment of the term “consisting essentially of”.
The term “oil-soluble” or “oil-dispersible” means that the compound can be soluble, dispersible, miscible or suspended in the oil in any proportion. Does not mean that. However, they are soluble or stably dispersed in the oil to the extent that the compound is sufficient to exert its intended effect, for example, in the environment in which the composition is used. It certainly means that you can. Moreover, the concomitant incorporation of other additives, such as those described above, can affect the solubility or dispersibility of the compound.
The term “major amount” means greater than 50% by weight of the composition.
The term “minor amount” means less than 50% by weight of the composition.

The present invention is further illustrated by the following examples, which should not be considered as limiting the scope of the invention. Every percentage is the content of active ingredient with respect to the additive on a mass basis, without considering the carrier or diluent.
A base lubricating oil composition was produced. The base oil is a succinimide dispersant, a calcium sulfonate detergent; a zinc dialkyldithiophosphate (ZDDP); a combination of antioxidants including hindered phenol, diphenylamine and sulfurized ester; a silicon-containing antifoam agent; a pour point depressant; A viscosity modifier was included. These ingredients were blended into API Group II base stock to produce the base lubricating oil composition.
A test oil was then prepared. One test oil contains the base lubricant as prepared above, with no additional additive components, and seven test oils were prepared by adding additional components to the base lubricant. . Details of these test oils are given in the table below, where the concentration of molybdenum in the test oil is expressed in parts per million (on a mass basis, relative to the mass of the test oil, as measured by ASTM D5185. ppm) and the amount of friction modifier added is also given in mass% relative to the mass of the test oil.

(c)：比較例

(c): Comparative example

Oils 1-6 and 10 are comparative examples, and oils 7, 8, 9 and 11 are examples according to the present invention. The polymeric organic friction modifier used was (i) maleated polyisobutylene (PIBSA), where the polyisobutylene group had an average molecular weight near 950 amu and an approximate saponification number of 98 mg KOH / g; (ii) reaction product of polyethylene glycol (PEG) having a hydroxyl number of 190 mg KOH / g; (iii) glycerol; and (iv) tall oil fatty acid. This was prepared as described above. Glycerol monooleate was chosen because it is a conventional friction modifier commonly used in lubricating oil compositions.
Each oil was tested using a Mini-Traction Machine (MTM-R) with reciprocating capability available from PCS Instruments in London, UK. It was. This tester uses a 19 mm (3/4 in) diameter ball as an upper test body that is reciprocated under an applied load against a lower test body in the shape of a disk. The balls were made of AIS152100 grade steel and were not coated. The disc was made of steel coated with DLC (Balinit ^™ DLC-Star: aC: H type) to a depth of around 2 μm. The contact between the ball and the disk was therefore between an iron-containing (steel) surface and a surface coated with a diamond-like carbon coating. The test conditions are given in the following table:

Zemetrics scope using wear-free scars formed on the lower disk-shaped specimen (DLC coated) using non-contact interferometric focal scanning (Zemetrics ZeScope) Analysis was performed using a 3D optical profilometer. This made it possible to measure the amount of wear by measuring the material lost from the disk under test. This was reported as a wear scar volume (WSV) expressed in units of μm ³ . In addition, the coefficient of friction for the contact area was recorded at the end of each test. The results are shown in the table below, where each value is the average of two tests with each test oil.

(c)：比較例

(c): Comparative example

  By comparing oils 1, 2, 3 and 10, it can be clearly seen that the presence of the molybdenum compound alone leads to significantly higher wear on the DLC surface. This confirms the observations reported by I. Sugimoto in Transactions of the Japan Society of Mechanical Engineers, Series A, Vol. 78, No. 786, pp. 213-222. Either the polymeric organic friction modifier (b) or the conventional glycerol monooleate friction modifier alone, the friction modifier alone was effective in reducing wear on the DLC surface. However, it did not give any significant decrease in the coefficient of friction (compare oil 1 with oils 4 and 5). The combination of the molybdenum compound and a conventional glycerol monooleate friction modifier gave good friction performance but resulted in low wear protection (compare oil 1 and oil 6). In contrast, the examples according to the invention (using oil 7, oil 8 and oil 9) provided both good wear protection and a low coefficient of friction. Oil 7 differs from Oil 2 only in the presence of the polymeric organic friction modifier (b), but this difference leads to a nearly 60% reduction in the recorded WSV and a low coefficient of friction. Is maintained. Similarly, Oil 8 differs from Oil 3 only in the presence of the polymeric organic friction modifier (b), which leads to a 85% reduction in the recorded WSV and lowers the coefficient of friction. Is maintained. Similarly, oil 9 showed good wear protection and a low coefficient of friction. Oil 10 also shows that a small amount of a single molybdenum compound leads to a significant increase in wear (compare oil 1). The addition of the polymeric organic friction modifier (b) restores wear protection and also provides a low coefficient of friction (Oil 11).

The above results show that, according to the present invention, the combination of the molybdenum compound and the specific type of polymer-based organic friction modifier (b) lubricates the contact between the DLC surface and the iron-containing (steel) surface. When used for this purpose, it shows that it is possible to provide a lubricating oil that protects the DLC surface from wear and also maintains low frictional contact. This behavior is not seen for ordinary types of friction modifiers. The combination of dinuclear molybdenum compound and trinuclear molybdenum compound (oil 8) gave the best overall performance in terms of good wear protection and low coefficient of friction. Thus, the present invention allows lubricant formulators to take advantage of the beneficial properties provided by molybdenum compounds in systems where the DLC surface is in contact with a surface containing iron.
Further test oils include succinimide dispersant; calcium sulfonate detergent; zinc dialkyldithiophosphate (ZDDP); a combination of antioxidants including hindered phenol, diphenylamine and sulfurized ester; silicon-containing antifoaming agent; pour point depression And a base lubricant containing a viscosity modifier. As above, the base stock used was an API Group II base stock. The following table details these test oils.

(c)：比較例

(c): Comparative example

Perfad ^™ 3006 is considered to be a polymeric organic friction modifier formed by the reaction of sorbitol, ethylene oxide and poly (12-hydroxystearic acid) as described in WO 2015/065801 It is done. Perfado 3006 is therefore chemically different from the polymeric organic friction modifier used in the present invention.
The MTM-R test as described above was performed on test oils 12-14 and the following results were obtained.

  As before, the presence of a single molybdenum compound leads to significantly higher wear on the DLC surface (compare oils 12 and 13). However, the combination of Perfado 3006 and the above molybdenum compound provided good friction performance, but the wear protection imparted to the DLC surface was not so remarkable. Comparison of oils 13 and 14 was related to the presence of the molybdenum compound alone, and the additional presence of Perfado 3006 resulted in a decrease in WSV of only 25%. This can be contrasted with the results for oils 2 and 7, where the presence of the polymeric organic friction modifier resulted in a 60% reduction in WSV. Thus, it is clear that the polymeric organic friction modifier used in the present invention is significantly more effective in preventing wear at steel-DLC contacts than Perfado 3006.

Claims (20)

  A first surface coated with a hydrogen-containing carbon film or coating of the type aC: H, ta-C: H, aC: H: Me or aC: H: X based on classification according to VDI-standard VDI 2840, and iron A method of lubricating a contact with a second surface, preferably made of steel, comprising the step of supplying a lubricating oil composition to the contact, the lubricating oil composition An oil having a high lubricating viscosity and (a) an oil-soluble or oil-dispersible molybdenum compound in an amount such that the lubricating oil composition provides 150 to 1,000 ppm of molybdenum by weight, and (b) ) With respect to the weight of the lubricating oil composition, comprising between 0.1 and 5% by weight of a polymeric organic friction modifier, the organic friction modifier comprising (i) a functionalized polyolefin, (ii) a polyether, The process as described above, which is a reaction product of iii) a polyol and (iv) a monocarboxylic acid chain terminating group   The oil-soluble molybdenum compound (a) is present in an amount to provide the lubricating oil composition with 300 to 1,000 ppm, preferably between 400 and 1,000 ppm molybdenum, by weight. Method.   The process according to claim 1 or 2, wherein the oil-soluble molybdenum compound (a) comprises one or more molybdenum dithiocarbamates.   4. The method of claim 3, wherein the oil-soluble molybdenum compound (a) comprises one or more dinuclear molybdenum dithiocarbamates or one or more trinuclear molybdenum dithiocarbamates.   The oil-soluble molybdenum compound (a) comprises a mixture of one or more dinuclear molybdenum compounds and one or more trinuclear molybdenum compounds. The method described in 1.   6. Process according to any one of claims 1 to 5, wherein the functionalized polyolefin (i) is derived from a polymer of mono-olefins having 2 to 6 carbon atoms.   7. A process according to any one of the preceding claims, wherein the functionalized polyolefin (i) comprises a diacid or anhydride functional group derived from the reaction of a polyolefin with an unsaturated diacid or anhydride.   The functionalized polyolefin (i) is a polyisobutylene polymer that has been reacted with maleic anhydride to form polyisobutylene succinic anhydride (PIBSA). The method described.   The method according to any one of claims 1 to 8, wherein the polyether (ii) comprises polyglycerol or polyalkylene glycol.   The process according to any one of claims 1 to 9, wherein the polyether (ii) comprises polyethylene glycol (PEG), mixed poly (ethylene-propylene) glycol or mixed poly (ethylene-butylene) glycol.   11. A process according to any one of claims 1 to 10, wherein polyol (iii) comprises a diol, triol, tetraol or related dimer, trimer or larger oligomer of such compounds.   The polyol (iii) is glycerol, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, pentaerythritol, dipentaerythritol, tripentaerythritol or sorbitol, preferably glycerol. 12. The method according to any one of claims 1 to 11, comprising. The carboxylic acid (iv) comprises a C ₂ -C ₃₆ carboxylic acid, preferably a C ₆ -C ₃₀ carboxylic acid, more preferably a C ₁₂ -C ₂₂ carboxylic acid, said acid being linear or branched, saturated or 13. A method according to any one of claims 1 to 12, which may be unsaturated.   The method according to any one of claims 1 to 13, wherein the carboxylic acid (iv) comprises one or more of lauric acid, erucic acid, isostearic acid, palmitic acid, oleic acid and linoleic acid. .   The polymeric friction modifier (b) comprises a reaction product of (i) maleated polyisobutylene (PIBSA), (ii) polyethylene glycol (PEG), (iii) glycerol and (iv) tall oil fatty acid. The method according to any one of 1 to 14.   The polymeric friction modifier (b) is present in the lubricating oil composition in an amount of between 0.1 and 3%, preferably 0.1 to 1.5% by weight, relative to the weight of the lubricating oil composition. 16. The method according to any one of 15.   One or more coated with a hydrogen-containing carbon film or coating of type aC: H, ta-C: H, aC: H: Me or aC: H: X based on classification according to VDI-standard VDI 2840 An internal combustion engine having components, wherein during operation of the engine, the components are in contact with a surface comprising iron, preferably steel, and a lubricating oil composition is contained in a reservoir in the engine An oil-solubility in an amount such that the composition contains an oil having a large amount of lubricating viscosity and (a) the lubricating oil composition provides between 150 and 1,000 ppm molybdenum by weight. Or an oil-dispersible molybdenum compound, and (b) between 0.1 and 5% by weight of a polymeric organic friction modifier with respect to the weight of the lubricating oil composition, the organic friction modifier comprising (i) a functional Polyolefins, (ii) polyethers, (iii) polyols and (iv) monocarboxylic acid chain terminating groups The internal combustion engine, which is a reaction product of   One or more coated with a hydrogen-containing carbon film or coating of type aC: H, ta-C: H, aC: H: Me or aC: H: X based on classification according to VDI-standard VDI 2840 Use of a lubricating oil composition for lubricating an internal combustion engine having components, wherein the components are in contact with a surface comprising iron, preferably steel, during operation of the engine, Oil-soluble or oil-dispersed in an amount such that the lubricating oil composition provides a large amount of oil of lubricating viscosity and (a) the lubricating oil composition provides between 150 and 1,000 ppm molybdenum by weight. And (b) 0.1 to 5% by weight of a polymeric organic friction modifier with respect to the weight of the lubricating oil composition, the organic friction modifier comprising (i) a functionalized polyolefin Reaction products of (ii) polyethers, (iii) polyols and (iv) monocarboxylic acid chain terminating groups Said use.   1 of internal combustion engines covered with hydrogen-containing carbon films or coatings of type aC: H, ta-C: H, aC: H: Me or aC: H: X based on the classification according to VDI-standard VDI 2840 Reduce friction and prevent wear between the seed or two or more components and one or more components of the internal combustion engine having a surface, preferably steel, containing iron A lubricating oil composition comprising: an oil having a large amount of lubricating viscosity; and (a) between 150 and 1,000 ppm of molybdenum on a mass basis to the lubricating oil composition. An amount of an oil-soluble or oil-dispersible molybdenum compound, and (b) between 0.1 and 5% by weight of a polymeric organic friction modifier, relative to the weight of the lubricating oil composition, The organic friction modifier comprises (i) a functionalized polyolefin, (ii) a polyether, (iii) a polyol and (iv) The use as described above, which is a reaction product of a monocarboxylic acid chain terminating group.   Lubricating oil composition further includes ashless dispersant, metal detergent, corrosion inhibitor, metal dihydrocarbyl dithiophosphate, antioxidant, pour point depressant, antifoaming agent, additional friction modifier, antiwear agent and viscosity modifier. The method according to any one of claims 1 to 16, the internal combustion engine according to claim 17 or claim 17, which also comprises one or more additional additives selected from the group consisting of agents. Item 20. Use according to Item 18 or 19.